Mirtazapine... the sedation is unreal.

So I have several conditions and dysautonomia is one of them. I was recommended mirtazapine, half a pill every night. I took one dose on Thursday night. I slept all night, all the way till midday. I literally woke up at 8, had breakfast and fell asleep again, no matter how hard I tried to stay awake. 8 am is the latest I wake up typically. Then had nausea after lunch; somehow I survived getting my hair done. By 8:30 p.m., I was falling asleep again. I skipped the next dose. Today I feel a bit less asleep, but still stupidly fatigued, and like I could fall asleep at any moment if I just close my eyes. It only took chopping some vegetables for lunch to feel all the fatigue in my body. I still have 13 days left until my next psychiatry appointment, and I can barely function. My chest feels extra heavy despite all that "rest". Would you keep taking it if you were me?